How does this medication work? What will it do for me?

Atazanavir belongs to the class of medications known as azapeptide HIV-1 protease inhibitors. It is used in combination with other medications to treat human immunodeficiency virus 1 (HIV-1) infection. HIV is the virus responsible for acquired immunodeficiency syndrome (AIDS). HIV infection destroys CD4 (T) cells, which are important to the immune system. The immune system helps fight infections.

Atazanavir reduces the amount of HIV in the blood by interfering with the enzyme protease that the HIV virus needs in order to multiply. Atazanavir may also help the immune system by increasing the number of CD4 (T) cells in the body.

This medication does not cure HIV infection or AIDS and does not reduce the risk of passing HIV on to others through sexual contact or blood contamination.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

150 mg
Each blue opaque cap and powder-blue opaque body, hard gelatin capsule, printed in white with "BMS", "150 mg", and in blue "3624" contains atazanavir sulfate equivalent to 150 mg of atazanavir. Nonmedicinal ingredients: crospovidone, lactose monohydrate, and magnesium stearate; capsule shell: FD&C Blue No. 2, gelatin, and titanium dioxide.

200 mg
Each blue opaque cap and body, hard gelatin capsule, printed in white with "BMS", "200 mg", and "3631" contains atazanavir sulfate equivalent to 200 mg of atazanavir. Nonmedicinal ingredients: crospovidone, lactose monohydrate, and magnesium stearate; capsule shell: FD&C Blue No. 2, gelatin, and titanium dioxide.

300 mg
Each red opaque cap and blue opaque body, hard gelatin capsule, printed in white with "BMS", "300 mg", and "3622" contains atazanavir sulfate equivalent to 300 mg of atazanavir. Nonmedicinal ingredients: crospovidone, lactose monohydrate, and magnesium stearate; capsule shell: black iron oxide, FD&C Blue No. 2, gelatin, red iron oxide, titanium dioxide, and yellow iron oxide.

How should I use this medication?

The recommended adult dose of atazanavir is 400 mg once daily with food. This medication should be taken at the same time each day and swallowed whole (do not open the capsules) with a glass of water.

If atazanavir is used in combination with the medication ritonavir, the recommended dose is 300 mg once a day. Atazanavir should never be used on its own and should always be used in combination with other HIV medications.

The recommended dose for children ages 6 to less than 18 are based on body weight and calculated by the doctor.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect from moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Atazanavir should not be taken by anyone who:

  • is allergic to atazanavir or to any of the ingredients of the medication
  • is taking any of the following medications:
    • bepridil
    • cisapride
    • ergot-type medications (i.e., dihydroergotamine, ergonovine, ergotamine, or methylergonovine)
    • indinavir
    • irinotecan
    • lovastatin
    • midazolam
    • nevirapine
    • omeprazole
    • pimozide
    • quinidine
    • rifampin
    • simvastatin
    • St. John's wort
    • triazolam
    • vardenafil
    • voriconazole
  • has or has had severe liver disease

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • diarrhea
  • difficulty sleeping
  • dizziness
  • headache
  • heartburn
  • nausea or vomiting (infrequent)

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • chest pain
  • changes in body fat distribution
  • confusion
  • fainting
  • nausea or vomiting (frequent)
  • rapid heartbeat
  • skin rash
  • stomach pain
  • weight loss
  • yellowing of skin or eyes (jaundice)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • signs of an allergic reaction (shortness of breath or difficulty breathing; hives; swelling of the eyes, mouth, lips, or throat)
  • signs of kidney stones (pain in your side, blood in urine, pain when urinating)
  • symptoms of a condition called lactic acidosis (unusual weakness or tiredness, unusual muscle pain, stomach pain with nausea and vomiting, feeling cold especially in arms and legs, dizziness or lightheadedness, and fast or irregular heartbeat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Body fat changes: People using atazanavir may notice the accumulation and redistribution of fat in their body. For example, less body fat on their arms, legs, and face, and more around the centre of their body (e.g., enlarged breasts, abdominal or central obesity, and a "buffalo hump" - a pad of fat on the back). The cause or long-term health effects of these changes are not known at this time.

Diabetes: Some people taking protease inhibitor medications such as atazanavir have developed diabetes during treatment, and some people who already had diabetes noticed that their diabetes became worse during treatment. People with diabetes should discuss with their doctor how this medication may affect their medical condition and whether any special monitoring is needed.

Heart effects: Atazanavir can affect the heart rhythm (heartbeat) in some people. People with problems in the electrical conduction system of their heart (e.g., first-, second-, and third-degree AV block) or who are taking medications that affect the electrical conduction system of the heart (e.g., diltiazem, verapamil) should discuss with their doctor how this medication may affect their medical condition and whether any special monitoring is needed.

Hemophilia: People with hemophilia A or B may be at an increased risk of bleeding while taking atazanavir and should discuss with their doctor how this medication may affect their medical condition and whether any special monitoring is needed.

Immune system: When you start taking HIV medications such as atazanavir, your immune system may get stronger and start to fight other infections that have been hidden in your body (e.g., pneumonia, herpes, or tuberculosis). Contact your doctor if you develop any new symptoms after starting HIV medications such as atazanavir.

Kidney stones: Some people taking atazanavir have developed kidney stones. If you develop signs or symptoms of kidney stones (e.g., pain in your side, blood in your urine, or pain when you urinate), contact your doctor immediately.

Lactic acidosis: People taking atazanavir in combination with some other HIV medications (e.g., abacavir, didanosine, lamivudine, stavudine, zalcitabine, and zidovudine) may be at risk of a serious condition called lactic acidosis. Lactic acidosis is a buildup of lactic acid in the blood. If you notice any of the symptoms of lactic acidosis, such as difficulty breathing, abdominal pain, muscle weakness, nausea, and vomiting, stop taking this medication and contact your doctor immediately.

Liver: This medication can cause liver problems. People with hepatitis B or C, or liver disease, may experience worsening of their liver disease symptoms while taking this medication. Your doctor will monitor your liver function while you are taking atazanavir. Report any signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools) to your doctor immediately. People with severe liver disease should not take this medication.

Other medications: Atazanavir may interact with a number of medications, which may mean a change in how you take this medication (see "What medications can interact with this medication?"). Tell your doctor of all medications that you are taking. Certain medications should not be taken with atazanavir at all (see "Who should NOT take this medication?").

Atazanavir should never be used on its own; it should always be used in combination with other HIV medications.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if atazanavir passes into breast milk. Breast-feeding is not recommended for HIV-positive women since the virus can be transmitted through breast milk.

Children and adolescents: The safety and effectiveness of using this medication have not been established for children and adolescents up to 16 years of age. Do not give this medication to children younger than 3 months as it can cause a form of brain damage known as kernicterus.

What other drugs could interact with this medication?

There may be an interaction between atazanavir and any of the following:

  • amiodarone
  • antacids and buffered medications
  • atenolol
  • atorvastatin
  • bepridil
  • buprenorphine
  • calcium channel blockers (e.g., diltiazem, felodipine, nicardipine, nifedipine, verapamil)
  • cisapride
  • clarithromycin
  • didanosine
  • efavirenz
  • ergotamine or ergot-type medications (e.g., dihydroergotamine, ergonovine, or methylergonovine)
  • ethinyl estradiol
  • famotidine
  • fluticasone propionate
  • immunosuppressants (e.g., cyclosporine, sirolimus, tacrolimus)
  • indinavir
  • irinotecan
  • itraconazole
  • ketoconazole
  • lidocaine (systemic)
  • lovastatin
  • midazolam
  • nevirapine
  • norethindrone
  • norgestimate
  • omeprazole
  • paclitaxel
  • phosphodiesterase (PDE 5) inhibitors (e.g., sildenafil, tadalafil, vardenafil)
  • pimozide
  • protease inhibitors (e.g., ritnonavir, saquinavir (soft gelatin capsules))
  • quinidine
  • repaglinide
  • rifabutin
  • rifampin
  • rosuvastatin
  • simvastatin
  • St. John's wort
  • tenofovir DF
  • trazadone
  • triazolam
  • tricyclic antidepressants (e.g., amitriptyline, desipramine, imipramine, nortriptyline)
  • voriconazole
  • warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.